Method and apparatus for making overlay and underlay paper



Feb. 13, 1923. 1,445,388.

I H. N. CASE.

METHOD AND APPARATUS FOR MAKING OVERLAY A ND UNDERLAY PAPER.

ORIGINAL FILED MAR. 5, 1919. 2 SHEETS-SHEET I.

Feb. 13, 1923. 1,445,388.

H. N. CASE.

METHOD AND APPARATUS FOR MAKING OVERLAY AND UNDEHLAY PAPER.

ORIGINAL nusu MM. 5. 1919. 2 SHEETS -SHEET 2.

Jul/wa jk'nr'c N Cane Jm Patented Feb. 13, 1923. 1

UNITED STATES PATENT OFFICE.

HENRY N. CASE, OF OAK PARK, ILLINOIS, ASSIGNOR 'IO SEARS, ROEBUCK AND CO., OF CHICAGO, ILLINOIS, A CORPORATION OF NEW YORK.

METHOD AND APPARATUS FOR MAKING OVERLAY AND UNDERLAY PAPER.

Original application filed March 5, 1919, Serial No. 280,750. Divided and this application filed April 1, 1920. Serial No. 370,542.

To all whom it may concern:

Be it known that I, HENRY N. CASE, a citizen of the United States, residing at Oak Park, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Methods and Apparatus for Making fOverlay and Underlay Paper, of which the following is a specification.

This invention relates to the manufacture of paper coated on both sides with material capable of being etched to produce reliefs suitable for use as matrices in subjecting printing plates to the McKee process. Great difficulty has been experienced providing a paper base with coatings of uniform thickness, and in handling the wet coated paper.

One object of my invention is to devise a method for coating the paper with a coating of great uniformity, and to provide eflicient and convenient drying means adapted to operate continuously and to deliver the dried product in suitable condition.

Further objects and advantages of my invention will become apparent-as the description proceeds. This application is'a division of my co-pending application, Serial No. 280,750.

In the accompanying drawings, Figure 1 is a fragmentary elevation of my device shown partially in section. Fig. 2 is a perspective view of the coating and carrying means. Fig. 3 is a detail view of a portion of the endless carrier. Figs. 4 and 5 are respectively longitudinal and transverse sectional views of the coating mechanism.

The paper to be coated may be of any suitable width, as, for example, eighteen inches, and is preferably supplied in the form of rolls of convenient diameter. In Fig. 1, A represents a roll of paper to be coated, the core of said roll having journals or trunnions A which are rotatably supported in any suitable way, as, for example, in standards 1 attached to a suitable fixed support. While various constructions for coating the paper may be employed, I have herein shown a tank 4 which is divided into two compartments 5 and 6 by means of a vertical partition 7. In the lower portion of the partition 7 is an oppening 8 which establishes communication between the two compartments. The tank 4 is filled by pouring the coating material into the compartment 6. 4" is a drain opening in the tank 4 for use in draining or cleaning the tank, said opening being normally closed by a plug 4". Any suitable means may be provided for heating the contents of the tank 4. Herein I have shown the tank as located Within a tank 9 capable of holding asuitable quantity of water, the water being heated by any convenient means, as, for example, an electric heater 9 of common construction.

10 is a frame or rack adapted to stand in the tank 4. YVithin the lower portion of the rack 10 is rotatably mounted a roller 11. It is desirable that the roller 11 be as light as possible and that it turn very freely in its bearings. 11 is a lock of any suitable construction for locking the roller 11 against rotation at will. ,Above and at one side of the roller 111 is a smaller roller 12. 12 indicates a lock of any desired character for holding the roller 12 against rotation at will. The web of paper unwound from the roll A passes over the upper edge of the partition 7, thence into contact with the roller 12, and thence around the roller 11, the paper being drawn through the bath by means hereinafter described.

With narrow paper, it is desirable that both rollers 11 and 12 be locked against rotation, particularly when the paper is deeply wire-marked. When the paper is over twelve inches wide, the roller 11 should be permitted to rotate freely. With a web more than eighteen inches wide, both rollers 11 and 12 should rotate.

The wiping action of the stationary submerged rollers upon the paper is desirable, and as much of such wiping should be employed as is practicable. However, the pamage of the web over a stationary roller places tension upon the web, and this factor limits the amount of wiping that can be permitted to occur. The wider the web the less tension should be placed. upon the submerged portion of the Web, in order to prevent the formation 'of longitudinal streaks from wrinkling, due to expansion of the paper when wet. Also the thinner the paper, the less must be the tension.

Vhen beginning operations, the rollers 11 and 12 are warmed by placing the rack 10 adjacent to any convenient source of heat,

after which the rack is laid on the tank 4. The web is then drawn through the space between the rollers and the rack is then care fully placed in the compartment 5.

In order to prevent the formation of small pits in the coating, it is necessary to keep the coating material free from particles of lint. greasy particles, or particles not necessarily greasy but not easily wet by water. The grinder, the coating machlne, and all utensils must be kept free from oil, grease and other substances not readily miscible with water.

In handling a coating as high in sizing as the one herein described, it is difficult to prevent foaming. The difficulty may, however, be obviated or cured by avoiding violent agitation, by repeated skimming, and by using two compartments in the coat ng machine so that the compartment in whlch the paper is coated receives its supply from the bottom of the compartment into which the coating is poured.

To prevent variations in the thickness of the coating, which manifest themselves in horizontal streaks, it is necessary that the paper be drawn through the bath at a uniform rate. If the paper be drawn through the bath too rapidly, streaks will form in all directions.

The paper may be dried in any suitable way, after which it is cut into sheets of convenient size, as, for example, 12x18 or 1T,L x22%. The sheets are then calendered in any suitable manner. as for example, by means of the plating method, a number of sheets being placed between zinc plates, and the whole run back and forth between two large cylinders under great pressure.

The apparatus shown in Fig. 1 is adapted to produce continuous movement of the web through the coating bath. As the coated paper leaves the bath. the coating is removed from both sides of both edge portions by any suitable means, as. for example. pairs of scraper blades 35. A space of about onefourth of an inch along each edge is thus freed from the coating material. After leaving the scrapers, the paper is carried by two endless narrow belts or tapes 36 each running over wheels 37. 38, 39, i0. 41. 4:2, 43 and 44. there being a set of such wheels for each belt 36. The wheels 38 are driven in any suitable way. as. for example, by a pulley 45 and belt T6, the pulley 45 being mounted on the shaft 17 of the wheels 38.

Opposite the wheels 3? are located wheels The belts 36 are provided with pin points 49 which puncture the uncoated edges of the web 'as the web passes between the wheels 37 and -18. The peripheries of the wheels T8 are grooved to accommodate the pin points 49.

The means shown in Fig. 1 for drying the paper consists of a casing 50 enclosing a suitable portion of the path of the paper. 51 is the air inlet and 52 the air outlet of the casing. A fan or the like (not shown) induces movement of air through the casing. Any suitable means, such as steam coils 53, may be provided to heat the air. In the particular arrangement herein shown, the web is supported on Wheels 54 during a portion of its travel, said wheels being peripherally grooved to accommodate the pin points. The dried web leaves the casing 50 through'the space 55 and is reeled up or otherwise handled as desired.

The coating material and the process herein disclosed produce a paper coated on both sides with a smooth, etchable coating of uniform thickness, and which will not shrink after etching.

\Vhile I- have herein referred to the paper as adapted for use in making McKee matrices, it will be understood that the paper has various other uses.

It is to be understood that the invention is. not limited to the constructions herein described, and that the dimensions, speed of operation and other quantitative features of the disclosure are merely illustrative.

I claim as my invention:

1. A web coating machine having, in combination, means for passing a continuous strip of material through a coating bath, means for removing the coating material from the edges of the strip after its passage through the bath, and conveying 100 means adapted to engage the edges of the strip from which the coating material has been removed and convey the strip through a dryer.

'2. A web coating machine having, in 105 combination. means for passing a continuous strip of material through a coating bath, and a pair of single endless conveyor belts operating by engagement only with relatively narrow edge portions of said 110 strip to receive the coated strip and convey it through a dryer.

3. A method of coating a strip of material comprisingi passing said strip continuously at a uniform speed through a coating 115 bath. removing certain portions of said coating. supporting said strip along said cleaned areas. and drying said strip while thus supported.

l. A web coating machine having, in 120 combination, a coating bath, means for passing a strip continuously through said coating bath, and. a conveyor comprising a pair of belts adapted to engage singly the respective edges of said strip. said belts 125 having projections adapted to perforate said strip.

5. A web coating machine having, in combination. a coating hath. means for passing a strip continuously through said 1 coating bath, and a conveyor comprising belts adapted to engage and singly support the edges of said strip, said belts having projections adapted to perforate said strip, and means for forcing said belts into contact with said strip and said projections through said strip at the point where said strip is received by said belt conveying mechanism.

6. A web-coating machine having, in combination, a coating hath, means for passing a strip continuously through said coating bath, scrapers supported above said bath for removing the coating material from the edges of the strip after its passage through the hath. and conveying means adapted to engage the cleaned edges of said strip.

In testimony wherof, I have hereunto set my hand.

HENRY N. CASE.

Certificate of Correetion.

It is hereby certified that in Letters Patent No. 1,445,388, granted February 13, 1923, upon t e application of Henry N. Case, of Oak Park, Illinois, for an improvement in Methods and i paratus for Making Overlay and Underlay Paper, an error appears in the prime; specification iequiring correction as follows: Page 3, after line 17, insert the following as claim 7:

7. A web-coating machine lid-02119, in combination, a coating bath, merited/or passing a strip continuously through said coating bath, a pair of single e ens conveyer belts adapted to engage and support the edges of said strip, said belts Iuz'uz'ng projections adapted to perforate sand strips, and a lurality of pulleys for guiding said belts, certain of said pulleys being grooved peripherally to accommodate said projectiom.; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflioe.

Signed and sealed this 20th day of March, A. D., 1923.

[BELL] KARL FENNING,

Acting Commissioner of Patents. 

